ERR_SYNC_LATENCY on HubSpot: Sync Latency / Payload Out-of-Order. Root cause: HubSpot property history sync is delayed or not updating in real-time. Common causes: property history tracking not enabled, sync frequency set to low (daily/weekly), API rate limits throttling updates, property history retention policy expired, integration batching updates instead of real-time sync. Step 1: Extract Event Timestamp. Inspect the incoming HubSpot payload envelope and locate the native eventId and occurredAt UNIX epoch millisecond values. Step 2: Check Target Database Record. Before saving changes to your data storage layer, query the existing record's local last_updated stamp. Step 3: Enforce Conditional Updates. Only overwrite local data arrays if the incoming occurredAt value is strictly greater than the date stamp currently residing in your database row. If it's older, discard the payload entirely.